Kepler measures spin rates of stars in Pleiades cluster

PASADENA, Calif., Aug. 12 (UPI) -- The latest mission by the Kepler space telescope has helped astronomers collect the most complete catalog of spin rates among the stars of the Pleiades cluster.

The new data is helping astronomers understand why stars in the cluster spin at varying rates, as well as how rotation periods relate to planet formation.

"We hope that by comparing our results to other star clusters, we will learn more about the relationship between a star's mass, its age, and even the history of its solar system," Luisa Rebull, a research scientist at Caltech's Infrared Processing and Analysis Center in Pasadena, said in a news release.

The Pleiades cluster is situated 445 light-years from Earth. Many of the stars in the cluster are just now reaching adulthood, having been born roughly 125 million years ago. They're spinning as fast as they ever will.

At their peak spin rates, these maturing stars eject large amounts of stellar wind. As these winds travel across the stars' magnetic fields, they enact a braking effect on the stars. As a star ages, its spin rate begins to slow down.

Kepler measures each star's spin rate by tracking the time between the appearance of recognizable starspots -- like sunspots.

The latest catalog of spin rates suggests more massive stars spin more slowly than less massive stars.

Rebull likens the stars to dancers, larger ones pirouetting more slowly than smaller ones.

"In the 'ballet' of the Pleiades, we see that slow rotators tend to be more massive, whereas the fastest rotators tend to be very light stars," said Rebull.

Because the Pleiades cluster is so close, it serves as an ideal cosmic laboratory to compare stellar qualities with spin rates.

"The Pleiades star cluster provides an anchor for theoretical models of stellar rotation going both directions, younger and older," said Rebull. "We still have a lot we want to learn about how, when and why stars slow their spin rates and hang up their 'dance shoes,' so to speak."

Rebull and her colleagues detailed their latest analysis of Pleiades spin rates in three new papers, soon to be published in the Astronomical Journal.